Sugarcane
About half of the sugar (sucrose) consumed today is extracted from sugarcane, a perennial grass; two centuries ago, all commercial sugar came from sugarcane. Sugarcane, or noble cane, comprises a group of hybrids found only in cultivation which cannot persist without cosseting by humans. Through 3,000 years, sugarcane had been transformed from a minor plant in the homegardens of Papua New Guineans. Gradually, it made its way across Asia and Africa before, in the fifteenth century, leaping into the New World and becoming a global agro-industrial crop. In the process, the Americas, Africa and Europe were changed, cultures exterminated and populations enslaved. In medieval Europe, sugar had been a rare and very expensive medicine, spice and condiment. Today, sugar is a commonplace preservative, food stuff and sweetener.
Sugarcane stems, which are packed with sucrose-filled, pulpy cells, can be up to six metres long and are made up of numerous near identical segments. Each segment comprises a bud, a rooting region, a ring of growing tissue and a long, sharp-edged leaf. The stem segments used to plant cane fields use their sucrose reserves to grow until their leaves emerge above ground and a vertical stem starts to elongate and produce its own sugars. In young stems, the main sugars are fructose and glucose but as the cane ripens the sugars are modified and stored as sucrose. After ten to 24 months, sucrose content is at its maximum and the cane may be harvested and sucrose extracted.
Sucrose extraction and concentration is a complex, skilled process, although the basic elements have not changed since the eighteenth century. Juice, squeezed from the cane stem, is boiled with lime to produce syrup. Once the scum has been removed, sucrose will crystallise as the concentrated syrup cools, producing a range of different types of commercial sugar. Planting and fertilising fields, harvesting cane and extracting sugar are labour-intensive processes. Consequently, sugarcane history is one of human exploitation and environmental destruction.
In the seventeenth and eighteenth centuries, sugar made Britain's fortune, and beverages, such as tea, coffee and chocolate, palatable. Global per capita sugar consumption has rapidly increased since this period, often disguised in all manner of unlikely foods. Consumers of sugar are killed sweetly and silently through obesity, Type II diabetics and heart disease, not to mention decaying teeth. Today, sugarcane is promoted as a raw material for the production of liquid biofuels such as ethanol.
Further reading
Abbott E 2010. Sugar. A bittersweet history. Pan.
Brazil Institute 2007. The global dynamics of biofuels. Potential supply and demand for ethanol and biodiesel in the coming decade. The Brazil Institute.
Warner JN 1962. Sugar cane: an indigenous Papuan cultigen. Ethnology 1: 405-411.
Stephen Harris